Really Creepy Teaser for 'Blindness' Surfaces

We thought this looked awesome last summer, and now we have some confirmation. MSN has posted a teaser trailer for Blindness, Fernando Meirelles' apocalyptic thriller based on the novel by José Saramago, and it creeps me out. The movie is about a blindness epidemic that sweeps through a city, afflicting everyone except one woman (Julianne Moore) who is apparently immune. She's then forced to feign blindness (Why? If no one else can see, what's the difference?) to care for her husband (Mark Ruffalo) as everything around them goes to hell. The tonal shift at the beginning of the teaser is genuinely startling, maybe because the upbeat music doesn't stop playing as you'd expect, or maybe because it deals with something that is one of this cinephile's worst nightmares.

I like Meirelles' City of God as much as the next guy, but the real reason I'm excited for this is that the screenplay is written by Don McKellar, whose previous stab at depicting the end of the world, Last Night, is one of my favorite films (with one of the most perfect endings of all time). Blindness is expected to play the Toronto Film Festival this September, with a US release slated for October. Can anyone who's read the book give us some (non-spoiler) hints of what to expect?